Inbred maize line PHOAA

ABSTRACT

An inbred maize line, designated PH0AA, the plants and seeds of inbred maize line PH0AA, methods for producing a maize plant produced by crossing the inbred line PH0AA with itself or with another maize plant, and hybrid maize seeds and plants produced by crossing the inbred line PH0AA with another maize line or plant.

FIELD OF THE INVENTION

This invention is in the field of maize breeding, specifically relatingto an inbred maize line designated PH0AA.

BACKGROUND OF THE INVENTION

The goal of plant breeding is to combine in a single variety or hybridvarious desirable traits. For field crops, these traits may includeresistance to diseases and insects, tolerance to heat and drought,reducing the time to crop maturity, greater yield, and better agronomicquality. With mechanical harvesting of many crops, uniformity of plantcharacteristics such as germination and stand establishment, growthrate, maturity, and plant and ear height, is important.

Field crops are bred through techniques that take advantage of theplant's method of pollination. A plant is self-pollinated if pollen fromone flower is transferred to the same or another flower of the sameplant. A plant is cross-pollinated if the pollen comes from a flower ona different plant.

Plants that have been self-pollinated and selected for type for manygenerations become homozygous at almost all gene loci and produce auniform population of true breeding progeny. A cross between twodifferent homozygous lines produces a uniform population of hybridplants that may be heterozygous for many gene loci. A cross of twoplants each heterozygous at a number of gene loci will produce apopulation of hybrid plants that differ genetically and will not beuniform.

Maize (zea mays L.), often referred to as corn in the United States, canbe bred by both self-pollination and cross-pollination techniques. Maizehas separate male and female flowers on the same plant, located on thetassel and the ear, respectively. Natural pollination occurs in maizewhen wind blows pollen from the tassels to the silks that protrude fromthe tops of the ears.

A reliable method of controlling male fertility in plants offers theopportunity for improved plant breeding. This is especially true fordevelopment of maize hybrids, which relies upon some sort of malesterility system. There are several options for controlling malefertility available to breeders, such as: manual or mechanicalemasculation (or detasseling), cytoplasmic male sterility, genetic malesterility, gametocides and the like.

Hybrid maize seed is typically produced by a male sterility systemincorporating manual or mechanical detasseling. Alternate strips of twoinbred varieties of maize are planted in a field, and the pollen-bearingtassels are removed from one of the inbreds (female). Providing thatthere is sufficient isolation from sources of foreign maize pollen, theears of the detasseled inbred will be fertilized only from the otherinbred (male), and the resulting seed is therefore hybrid and will formhybrid plants.

The laborious, and occasionally unreliable, detasseling process can beavoided by using cytoplasmic male-sterile (CMS) inbreds. Plants of a CMSinbred are male sterile as a result of factors resulting from thecytoplasmic, as opposed to the nuclear, genome. Thus, thischaracteristic is inherited exclusively through the female parent inmaize plants, since only the female provides cytoplasm to the fertilizedseed. CMS plants are fertilized with pollen from another inbred that isnot male-sterile. Pollen from the second inbred may or may notcontribute genes that make the hybrid plants male-fertile. Usually seedfrom detasseled fertile maize and CMS produced seed of the same hybridare blended to insure that adequate pollen loads are available forfertilization when the hybrid plants are grown.

There are several methods of conferring genetic male sterilityavailable, such as multiple mutant genes at separate locations withinthe genome that confer male sterility, as disclosed in U.S. Pat. Nos.4,654,465 and 4,727,219 to Brar et al. and chromosomal translocations asdescribed by Patterson in U.S. Pat. Nos. 3,861,709 and 3,710,511. Theseand all patents referred to are incorporated by reference. In additionto these methods, Albertsen et al., of Pioneer Hi-Bred, U.S. patentapplication Ser. No. 07/848,433, have developed a system of nuclear malesterility which includes: identifying a gene which is critical to malefertility; silencing this native gene which is critical to malefertility; removing the native promoter from the essential malefertility gene and replacing it with an inducible promoter; insertingthis genetically engineered gene back into the plant; and thus creatinga plant that is male sterile because the inducible promoter is not "on"resulting in the male fertility gene not being transcribed. Fertility isrestored by inducing, or turning "on", the promoter, which in turnallows the gene that confers male fertility to be transcribed.

There are many other methods of conferring genetic male sterility in theart, each with its own benefits and drawbacks. These methods use avariety of approaches such as delivering into the plant a gene encodinga cytotoxic substance associated with a male tissue specific promoter oran antisense system in which a gene critical to fertility is identifiedand an antisense to that gene is inserted in the plant (see:Fabinjanski, et al. EPO 89/3010153.8 publication no. 329,308 and PCTapplication PCT/CA90/00037 published as WO 90/08828).

Another system useful in controlling male sterility makes use ofgametocides. Gametocides are not a genetic system, but rather a topicalapplication of chemicals. These chemicals affect cells that are criticalto male fertility. The application of these chemicals affects fertilityin the plants only for the growing season in which the gametocide isapplied (see Carlson, Glenn R., U.S. Pat. No. 4,936,904). Application ofthe gametocide, timing of the application and genotype specificity oftenlimit the usefulness of the approach.

The use of male sterile inbreds is but one factor in the production ofmaize hybrids. The development of maize hybrids requires, in general,the development of homozygous inbred lines, the crossing of these lines,and the evaluation of the crosses. Pedigree breeding and recurrentselection breeding methods are used to develop inbred lines frombreeding populations. Breeding programs combine the genetic backgroundsfrom two or more inbred lines or various other broad-based sources intobreeding pools from which new inbred lines are developed by selfing andselection of desired phenotypes. The new inbreds are crossed with otherinbred lines and the hybrids from these crosses are evaluated todetermine which of those have commercial potential.

Pedigree breeding starts with the crossing of two genotypes, each ofwhich may have one or more desirable characteristics that is lacking inthe other or which complements the other. If the two original parents donot provide all the desired characteristics, other sources can beincluded in the breeding population. In the pedigree method, superiorplants are selfed and selected in successive generations. In thesucceeding generations the heterozygous condition gives way tohomogeneous lines as a result of self-pollination and selection.Typically in the pedigree method of breeding five or more generations ofselfing and selection is practiced: F₁ →F₂ ; F₃ →F₄ ; F₄ →F₅, etc.

Recurrent selection breeding, backcrossing for example, can be used toimprove an inbred line. Backcrossing can be used to transfer a specificdesirable trait from one inbred or source to an inbred that lacks thattrait. This can be accomplished, for example, by first crossing asuperior inbred (recurrent parent) to a donor inbred (non-recurrentparent), that carries.the appropriate gene(s) for the trait in question.The progeny of this cross is then mated back to the superior recurrentparent followed by selection in the resultant progeny for the desiredtrait to be transferred from the nonrecurrent parent. After five or morebackcross generations with selection for the desired trait, the progenywill be heterozygous for loci controlling the characteristic beingtransferred, but will be like the superior parent for most or almost allother genes. The last backcross generation is then selfed to give purebreeding progeny for the gene(s) being transferred.

A single cross hybrid maize variety is the cross of two inbred lines,each of which has a genotype that complements the genotype of the other.The hybrid progeny of the first generation is designated F₁. In thedevelopment of hybrids only the F₁. hybrid plants are sought. PreferredF₁, hybrids are more vigorous than their inbred parents. This hybridvigor, or heterosis, can be manifested in many polygenic traits,including increased vegetative growth and increased yield.

The development of a hybrid maize variety involves three steps: (1) theselection of plants from various germplasm pools for initial breedingcrosses; (2) the selfing of the selected plants from the breedingcrosses for several generations to produce a series of inbred lines,which, although different from each other, breed true and are highlyuniform; and (3) crossing the selected inbred lines with differentinbred lines to produce the hybrid progeny (F₁). During the inbreedingprocess in maize, the vigor of the lines decreases. Vigor is restoredwhen two different inbred lines are crossed to produce the hybridprogeny (F₁). An important consequence of the homozygosity andhomogeneity of the inbred lines is that the hybrid between a definedpair of inbreds will always be the same. Once the inbreds that give asuperior hybrid have been identified, the hybrid seed can be reproducedindefinitely as long as the homogeneity of the inbred parents ismaintained.

A single cross hybrid is produced when two inbred lines are crossed toproduce the F₁ progeny. A double cross hybrid is produced from fourinbred lines crossed in pairs (A×B and C×D) and then the two F₁ hybridsare crossed again (A×B)×(C×D). Much of the hybrid vigor exhibited by F₁hybrids is lost in the next generation (F₂). Consequently, seed fromhybrid varieties is not used for planting stock.

Maize is an important and valuable field crop. Thus, a continuing goalof plant breeders is to develop high-yielding maize hybrids that areagronomically sound based on stable inbred lines. The reasons for thisgoal are obvious: to maximize the amount of grain produced with theinputs used and minimize susceptibility of the crop to environmentalstresses. To accomplish this goal, the maize breeder must select anddevelop superior inbred parental lines for producing hybrids. Thisrequires identification and selection of genetically unique individualsthat occur in a segregating population. The segregating population isthe result of a combination of crossover events plus the independentassortment of specific combinations of alleles at many gene loci thatresults in specific genotypes. Based on the number of segregating genes,the frequency of occurrence of an individual with a specific genotype isless than 1 in 10,000. Thus, even if the entire genotype of the parentshas been characterized and the desired genotype is known, only a few ifany individuals having the desired genotype may be found in a large F₂or S₀ population. Typically, however, the genotype of neither theparents nor the desired genotype is known in any detail.

In addition to the preceding problem, it is not known how the genotypewill react with the environment. This genotype by environmentinteraction is an important, yet unpredictable, factor in plantbreeding. A breeder of ordinary skill in the art cannot predict thegenotype, how that genotype will interact with various environments orthe resulting phenotypes of the developing lines, except perhaps in avery broad and general fashion. A breeder of ordinary skill in the artwould also be unable to recreate the same line twice from the very sameoriginal parents as the breeder is unable to direct how the genomescombine or how they will interact with the environmental conditions.This unpredictability results in the expenditure of large amounts ofresearch resources in the development of a superior new maize inbredline.

Pioneer research station staff propose about 400 to 500 new inbreds eachyear from over 2,000,000 pollinations. Of those proposed new inbreds,less than 50 and more commonly less than 30 are actually selected forcommercial use.

SUMMARY OF THE INVENTION

According to the invention, there is provided a novel inbred maize line,designated PH0AA. This invention thus relates to the seeds of inbredmaize line PH0AA, to the plants of inbred maize line PH0AA, and tomethods for producing a maize plant produced by crossing the inbred linePH0AA with itself or another maize line. This invention further relatesto hybrid maize seeds and plants produced by crossing the inbred linePH0AA with another maize line.

Definitions

In the description and examples that follow, a number of terms are usedherein. In order to provide a clear and consistent understanding of thespecification and claims, including the scope to be given such terms,the following definitions are provided. NOTE: ABS is in absolute termsand % MN is percent of the mean for the experiments in which the inbredor hybrid was grown. These designators will follow the descriptors todenote how the values are to be interpreted. Below are the descriptorsused in the data tables included herein.

ANT ROT=ANTHRACNOSE STALK ROT (Colletotrichum graminicola). A 1 to 9visual rating indicating the resistance to Anthracnose Stalk Rot Ahigher score indicates a higher resistance.

BAR PLT=BARREN PLANTS. The percent of plants per plot that were notbarren (lack ears).

BRT STK=BRITTLE STALKS. This is a measure of the stalk breakage near thetime of pollination, and is an indication of whether a hybrid or inbredwould snap or break near the time of flowering under severe winds. Dataare presented as percentage of plants that did not snap.

BU ACR=YIELD (BUSHELS/ACRE). Yield of the grain at harvest in bushelsper acre adjusted to 15.5% moisture.

CLD TST=COLD TEST. The percent of plants that germinate under cold testconditions.

CLN=CORN LETHAL NECROSIS. Synergistic interaction of maize chloroticmottle virus (MCMV) in combination with either maize dwarf mosaic virus(MDMV-A or MDMV-B) or wheat streak mosaic virus (WSMV). A 1 to 9 visualrating indicating the resistance to Corn Lethal Necrosis. A higher scoreindicates a higher resistance.

COM RST=COMMON RUST (Puccinia sorghi). A 1 to 9 visual rating indicatingthe resistance to Common Rust. A higher score indicates a higherresistance.

D/D=DRYDOWN. This represents the relative rate at which a hybrid willreach acceptable harvest moisture compared to other hybrids on a 1-9rating scale. A high score indicates a hybrid that dries relatively fastwhile a low score indicates a hybrid that dries slowly.

DIP ERS=DIPLODIA EAR MOLD SCORES (Diplodia maydis and Diplodiamacrospora). A 1 to 9 visual rating indicating the resistance toDiplodia Ear Mold. A higher score indicates a higher resistance.

DRP EAR=DROPPED EARS. A measure of the number of dropped ears per plotand represents the percentage of plants that did not drop ears prior toharvest.

D/T=DROUGHT TOLERANCE. This represents a 1-9 rating for droughttolerance, and is based on data obtained under stress conditions. A highscore indicates good drought tolerance and a low score indicates poordrought tolerance.

EAR HT=EAR HEIGHT. The ear height is a measure from the ground to thehighest placed developed ear node attachment and is measured in inches.

EAR MLD=General Ear Mold. Visual rating (1-9 score) where a "1" is verysusceptible and a "9" is very resistant. This is based on overall ratingfor ear mold of mature ears without determining the specific moldorganism, and may not be predictive for a specific ear mold.

EAR SZ=EAR SIZE. A 1 to 9 visual rating of ear size. The higher therating the larger the ear size.

ECB 1LF=EUROPEAN CORN BORER FIRST GENERATION LEAF FEEDING (Ostrinianubilalis). A 1 to 9 visual rating indicating the resistance topreflowering leaf feeding by first generation European Corn Borer. Ahigher score indicates a higher resistance.

ECB 2IT=EUROPEAN CORN BORER SECOND GENERATION INCHES OF TUNNELING(Ostrinia nubilalis). Average inches of tunneling per plant in thestalk.

ECB 2SC=EUROPEAN CORN BORER SECOND GENERATION (Ostrinia nubilalis). A 1to 9 visual rating indicating post flowering degree of stalk breakageand other evidence of feeding by European Corn Borer, Second Generation.A higher score indicates a higher resistance.

ECB DPE=EUROPEAN CORN BORER DROPPED EARS (Ostrinia nubilalis). Droppedears due to European Corn Borer. Percentage of plants that did not dropears under second generation corn borer infestation.

EST CNT=EARLY STAND COUNT. This is a measure of the stand establishmentin the spring and represents the number of plants that emerge on perplot basis for the inbred or hybrid.

EYE SPT=Eye Spot (Kabatiella zeae or Aureobasidium zeae). A 1 to 9visual rating indicating the resistance to Eye Spot. A higher scoreindicates a higher resistance.

FUS ERS=FUSARIUM EAR ROT SCORE (Fusarium moniliforme or Fusariumsubglutinans). A 1 to 9 visual rating indicating the resistance toFusarium ear rot. A higher score indicates a higher resistance.

GDU=Growing Degree Units. Using the Barger Heat Unit Theory, whichassumes that maize growth occurs in the temperature range 50° F.-86° F.and that temperatures outside this range slow down growth; the maximumdaily heat unit accumulation is 36 and the minimum daily heat unitaccumulation is 0. The seasonal accumulation of GDU is a major factor indetermining maturity zones.

GDU SHD=GDU TO SHED. The number of growing degree units (GDUs) or heatunits required for an inbred line or hybrid to have approximately 50percent of the plants shedding pollen and is measured from the time ofplanting. Growing degree units are calculated by the Barger Method,where the heat units for a 24-hour period are: ##EQU1##

The highest maximum temperature used is 86° F. and the lowest minimumtemperature used is 50° F. For each inbred or hybrid it takes a certainnumber of GDUs to reach various stages of plant development.

GDU SLK=GDU TO SILK. The number of growing degree units required for aninbred line or hybrid to have approximately 50 percent of the plantswith silk emergence from time of planting. Growing degree units arecalculated by the Barger Method as given in GDU SHD definition.

GIB ERS=GIBBERELLA EAR ROT (PINK MOLD) (Gibberella zeae). A 1 to 9visual rating indicating the resistance to Gibberella Ear Rot. A higherscore indicates a higher resistance.

GLF SPT=Gray Leaf Spot (Cercospora zeae-maydis). A 1 to 9 visual ratingindicating the resistance to Gray Leaf Spot. A higher score indicates ahigher resistance.

GOS WLT=Goss' Wilt (Corynebacterium nebraskense). A 1 to 9 visual ratingindicating the resistance to Goss' Wilt. A higher score indicates ahigher resistance.

GRN APP=GRAIN APPEARANCE. This is a 1 to 9 rating for the generalappearance of the shelled grain as it is harvested based on such factorsas the color of harvested grain, any mold on the grain, and any crackedgrain. High scores indicate good grain quality.

H/POP=YIELD AT HIGH DENSITY. Yield ability at relatively high plantdensities on 1-9 relative rating system with a higher number indicatingthe hybrid responds well to high plant densities for yield relative toother hybrids. A 1, 5, and 9 would represent very poor, average, andvery good yield response, respectively, to increased plant density.

HC BLT=HELMINTHOSPORIUM CARBONUM LEAF BLIGHT (Helminthosporiumcarbonum). A 1 to 9 visual rating indicating the resistance toHelminthosporium infection. A higher score indicates a higherresistance.

HD SMT=HEAD SMUT (Sphacelotheca reiliana). This score indicates thepercentage of plants not infected.

INC D/A=GROSS INCOME (DOLLARS PER ACRE). Relative income per acreassuming drying costs of two cents per point above 15.5 percent harvestmoisture and current market price per bushel.

INCOME/ACRE. Income advantage of hybrid to be patented over other hybridon per acre basis.

INC ADV=GROSS INCOME ADVANTAGE. GROSS INCOME advantage of variety #1over variety #2.

KSZ DCD=KERNEL SIZE DISCARD. The percent of discard seed; calculated asthe sum of discarded tip kernels and extra large kernels.

L/POP=YIELD AT LOW DENSITY. Yield ability at relatively low plantdensities on a 1-9 relative system with a higher number indicating thehybrid responds well to low plant densities for yield relative to otherhybrids. A 1, 5, and 9 would represent very poor, average, and very goodyield response, respectively, to low plant density.

MDM CPX=MAIZE DWARF MOSAIC COMPLEX (MDMV=Maize Dwarf Mosaic Virus andMCDV=Maize Chlorotic Dwarf Virus). A 1 to 9 visual rating indicating theresistance to Maize Dwarf Mosaic Complex. A higher score indicates ahigher resistance.

MST=HARVEST MOISTURE. The moisture is the actual percentage moisture ofthe grain at harvest.

MST ADV=MOISTURE ADVANTAGE. The moisture advantage of variety #1 overvariety #2 as calculated by: MOISTURE of variety #2-MOISTURE of variety#1=MOISTURE ADVANTAGE of variety #1.

NLF BLT=Northern Leaf Blight (Helminthospodum turcicum or Exserohilumturcicum). A 1 to 9 visual rating indicating the resistance to NorthernLeaf Blight. A higher score indicates a higher resistance.

PLT HT=PLANT HEIGHT. This is a measure of the height of the plant fromthe ground to the tip of the tassel in inches.

POL SC=POLLEN SCORE. A 1 to 9 visual rating indicating the amount ofpollen shed. The higher the score the more pollen shed.

POL WT=POLLEN WEIGIHT. This is calculated by dry weight of tasselscollected as shedding commences minus dry weight from similar tasselsharvested after shedding is complete.

It should be understood that the inbred can, through routinemanipulation of cytoplasmic or other factors, be produced in amale-sterile form. Such embodiments are also contemplated within thescope of the present claims.

POP K/A=PLANT POPULATIONS. Measured as 1000s per acre.

POP ADV=PLANT POPULATION ADVANTAGE. The plant population advantage ofvariety #1 over variety #2 as calculated by PLANT POPULATION of variety#2-PLANT POPULATION of variety #1=PLANT POPULATION ADVANTAGE of variety#1.

PRM=PREDICTED RELATIVE MATURITY. This trait, predicted relativematurity, is based on the harvest moisture of the grain. The relativematurity rating is based on a known set of checks and utilizes standardlinear regression analyses and is also referred to as the ComparativeRelative Maturity Rating System that is similar to the MinnesotaRelative Maturity Rating System.

PRM SHD=A relative measure of the growing degree units (GDU) required toreach 50% pollen shed. Relative values are predicted values from thelinear regression of observed GDU's on relative maturity of commercialchecks.

RT LDG=ROOT LODGING. Root lodging is the percentage of plants that donot root lodge; plants that lean from the vertical axis at anapproximately 30° angle or greater would be counted as root lodged.

RTL ADV=ROOT LODGING ADVANTAGE. The root lodging advantage of variety #1over variety #2.

SCT GRN=SCATTER GRAIN. A 1 to 9 visual rating indicating the amount ofscatter grain (lack of pollination or kernel abortion) on the ear. Thehigher the score the less scatter grain.

SDG VGR=SEEDLING VIGOR. This is the visual rating (1 to 9) of the amountof vegetative growth after emergence at the seedling stage(approximately five leaves). A higher score indicates better vigor.

SEL IND=SELECTION INDEX. The selection index gives a single measure ofthe hybrid's worth based on information for up to five traits. A maizebreeder may utilize his or her own set of traits for the selectionindex. One of the traits that is almost always included is yield. Theselection index data presented in the tables represent the mean valueaveraged across testing stations.

SLF BLT=SOUTHERN LEAF BLIGHT (Helminthosporium maydis or Bipolarismaydis). A 1 to 9 visual rating indicating the resistance to SouthernLeaf Blight. A higher score indicates a higher resistance.

SOU RST=SOUTHERN RUST (Puccinia polysora). A 1 to 9 visual ratingindicating the resistance to Southern Rust. A higher score indicates ahigher resistance.

STA GRN=STAY GREEN. Stay green is the measure of plant health near thetime of black layer formation (physiological maturity). A high scoreindicates better late-season plant health.

STD ADV=STALK STANDING ADVANTAGE. The advantage of variety #1 overvariety #2 for the trait STK CNT.

STK CNT=NUMBER OF PLANTS. This is the final stand or number of plantsper plot.

STK LDG=STALK LODGING. This is the percentage of plants that did notstalk lodge (stalk breakage) as measured by either natural lodging orpushing the stalks and determining the percentage of plants that breakbelow the ear.

STW WLT=Stewart's Wilt (Erwinia stewartii). A 1 to 9 visual ratingindicating the resistance to Stewart's Wilt. A higher score indicates ahigher resistance.

TAS BLS=TASSEL BLAST. A 1 to 9 visual rating was used to measure thedegree of blasting (necrosis due to heat stress) of the tassel at thetime of flowering. A 1 would indicate a very high level of blasting attime of flowering, while a 9 would have no tassel blasting.

TAS SZ=TASSEL SIZE. A 1 to 9 visual rating was used to indicate therelative size of the tassel. The higher the rating the larger thetassel.

TAS WT=TASSEL WEIGHT. This is the average weight of a tassel (grams)just prior to pollen shed.

TEX EAR=EAR TEXTURE. A 1 to 9 visual rating was used to indicate therelative hardness (smoothness of crown) of mature grain. A 1 would bevery soft (extreme dent) while a 9 would be very hard (flinty or verysmooth crown).

TILLER=TILLERS. A count of the number of tillers per plot that couldpossibly shed pollen was taken. Data is given as a percentage oftillers: number of tillers per plot divided by number of plants perplot.

TST WT=TEST WEIGHT (UNADJUSTED). The measure of the weight of the grainin pounds for a given volume (bushel).

TST WTA=TEST WEIGHT ADJUSTED. The measure of the weight of the grain inpounds for a given volume (bushel) adjusted for 15.5 percent moisture.

TSW ADV=TEST WEIGHT ADVANTAGE. The test weight advantage of variety #1over variety #2.

WIN M%=PERCENT MOISTURE WINS.

WIN Y%=PERCENT YIELD WINS.

YLD=YIELD. It is the same as BU ACR ABS.

YLD ADV=YIELD ADVANTAGE. The yield advantage of variety #1 over variety#2 as calculated by: YIELD of variety #1-YIELD variety #2=yieldadvantage of variety #1.

YLD SC=YIELD SCORE. A 1 to 9 visual rating was used to give a relativerating for yield based on plot ear piles. The higher the rating thegreater visual yield appearance.

DETAILED DESCRIPTION OF THE INVENTION

Inbred maize lines are typically developed for use in the production ofhybrid maize lines. Inbred maize lines need to be highly homogeneous,homozygous and reproducible to be useful as parents of commercialhybrids. There are many analytical methods available to determine thehomozygotic and phenotypic stability of these inbred lines.

The oldest and most traditional method of analysis is the. observationof phenotypic traits. The data is usually collected in field experimentsover the life of the maize plants to be examined. Phenotypiccharacteristics most often observed are for traits associated with plantmorphology, ear and kernel morphology, insect and disease resistance,maturity, and yield.

In addition to phenotypic observations, the genotype of a plant can alsobe examined. There are many laboratory-based techniques available forthe analysis, comparison and characterization of plant genotype; amongthese are Isozyme Electrophoresis, Restriction Fragment LengthPolymorphisms (RFLPs), Randomly Amplified Polymorphic DNAs (RAPDs),Arbitrarily Primed Polymerase Chain Reaction (AP-PCR), DNA AmplificationFingerprinting (DAF), Sequence Characterized Amplified Regions (SCARs),Amplified Fragment Length Polymorphisms (AFLPs), and Simple SequenceRepeats (SSRs) which are also referred to as Microsatellites.

The most widely used of these laboratory techniques are IsozymeElectrophoresis and RFLPs as discussed in Lee, M., "Inbred Lines ofMaize and Their Molecular Markers," The Maize Handbook,(Springer-Verlag, N.Y., Inc. 1994, at 423-432) incorporated herein byreference. Isozyme Electrophoresis is a useful tool in determininggenetic composition, although it has relatively low number of availablemarkers and the low number of allelic variants among maize inbreds.RFLPs have the advantage of revealing an exceptionally high degree ofallelic variation in maize and the number of available markers is almostlimitless.

Maize RFLP linkage maps have been rapidly constructed and widelyimplemented in genetic studies. One such study is described inBoppenmaier, et al., "Comparisons among strains of inbreds for RFLPs",Maize Genetics Cooperative Newsletter, 65:1991, pg. 90, is incorporatedherein by reference. This study used 101 RFLP markers to analyze thepatterns of 2 to 3 different deposits each of five different inbredlines. The inbred lines had been selfed from 9 to 12 times before beingadopted into 2 to 3 different breeding programs. It was results fromthese 2 to 3 different breeding programs that supplied the differentdeposits for analysis. These five lines were maintained in the separatebreeding programs by selfing or sibbing and rogueing off-type plants foran additional one to eight generations. After the RFLP analysis wascompleted, it was determined the five lines showed 0-2% residualheterozygosity. Although this was a relatively small study, it can beseen using RFLPs that the lines had been highly homozygous prior to theseparate strain maintenance.

Inbred maize line PH0AA is a yellow dent-like maize inbred that is bestsuited as a male in crosses for producing first generation F₁ maizehybrids. Inbred maize line PH0AA is best adapted to the Northcentralregion of the United States and can be used to produce hybrids ofapproximately 101 relative maturity based on the Comparative RelativeMaturity Rating System for harvest moisture of grain. Inbred maize linePH0AA demonstrates good early stand count and stalk count. In hybridcombination, PH0AA demonstrates very good seedling vigor and very goodresistance to brittle stalk. For its area of adaptation, PH0AAdemonstrates stable yield performance and good resistance to brittlestalk.

The inbred has shown uniformity and stability within the limits ofenvironmental influence for all the traits as described in the VarietyDescription Information (Table 1) that follows. The inbred has beenself-pollinated and ear-rowed a sufficient number of generations withcareful attention paid to uniformity of plant type to ensure thehomozygosity and phenotypic stability necessary to use in commercialproduction. The line has been increased both by hand and in isolatedfields with continued observation for uniformity. No variant traits havebeen observed or are expected in PH0AA.

Inbred maize line PH0AA, being substantially homozygous, can bereproduced by planting seeds of the line, growing the resulting maizeplants under self-pollinating or sib-pollinating conditions withadequate isolation, and harvesting the resulting seed, using techniquesfamiliar to the agricultural arts.

                  TABLE 1                                                         ______________________________________                                        VARIETY DESCRIPTION INFORMATION                                               INBRED = PH0AA                                                                Type:                                                                              Dent Like                                                                ______________________________________                                        A.   Maturity: Average across maturity zones.                                      GDU Shed: 1370                                                                GDU Silk: 1380                                                                No. Reps: 2                                                              B.   Plant Characteristics:                                                        Plant height (to tassel tip): 164 cm                                          Length of top ear internode: 11 cm                                            Number of ears per stalk: Single                                              Ear height (to base of top ear): 56 cm                                        Number of tillers: None                                                  C.   Leaf:                                                                         Color: (B14) Dark Green*                                                      Angle from Stalk: <30 degrees                                                 Marginal Waves: (WF9) Few                                                     Number of Leaves (mature plants): 18                                          Sheath Pubescence: (W22) Light                                                Longitudinal Creases: (PA11) Many                                             Length (Ear node leaf): 54 cm                                                 Width (widest point, ear node leaf): 9 cm                                D.   Tassel:                                                                       Number lateral branches: 3                                                    Branch Angle from central spike: >45 degrees                                  Pollen Shed: Heavy (KY21)                                                     Peduncle Length (top leaf to basal branches): 26 cm                           Anther Color: Green*                                                          Glume Color: Green*                                                      E.   Ear (Husked Ear Data Except When Stated Otherwise):                           Length: 13 cm                                                                 Weight: 74 gm                                                                 Mid-point Diameter: 37 mm                                                     Silk Color: Green*                                                            Husk Extension (Harvest stage): Medium (Barely Covering Ear)                  Husk Leaf: Long (>15 cm)                                                      Taper of Ear: Average                                                         Position of Shank (dry husks): Drooping                                       Kernel Rows: Straight, Distinct Number = 15                                   Husk Color (fresh): Light Green*                                              Husk Color (dry): Buff*                                                       Shank Length: 9 cm                                                            Shank (No. of internodes): 10                                            F.   Kernel (Dried):                                                               Size (from ear mid-point)                                                     Length: 10 mm                                                                 Width: 8 mm                                                                   Thick: 5 mm                                                                   Shape Grade (% rounds) 20-40                                                  Pericarp Color: Colorless*                                                    Aleurone Color: Homozygous Yellow*                                            Endosperm Color: Yellow*                                                      Endosperm Type: Normal Starch                                                 Gm Wt/100 Seeds (unsized): 24 gm                                         G.   Cob:                                                                          Diameter at mid-point: 20 mm                                                  Strength: Strong                                                              Color: White*                                                            H.   Diseases:                                                                     Goss's Wilt (C. nebraskense): Resistant                                  I.   Insects:                                                                      European Corn Borer-1 Leaf Damage (Pre-flowering): Intermediate               European Corn Borer-2 (Post-flowering): Intermediate                          The above descriptions are based on a scale of 1-9, 1 being highly            susceptible, 9 being highly resistant.                                        S (Susceptible): Would generally represent a score of 1-3.                    I (Intermediate): Would generally represent a score of 4-5.                   R (Resistant): Would generally represent a score of 6-7.                      H (Highly Resistant): Would generally represent a score of 8-9.               Highly resistant does not imply the inbred is immune.                    ______________________________________                                         *In interpreting the foregoing color designations, reference may be had t     the Munsell                                                                   Glossy Book of Color, a standard color reference.                        

Industrial Applicability

This invention also is directed to methods for producing a maize plantby crossing a first parent maize plant with a second parent maize plantwherein the first or second parent maize plant is an inbred maize plantof the line PH0AA. Further, both first and second parent maize plantscan come from the inbred maize line PH0AA. Thus, any such methods usingthe inbred maize line PH0AA are part of this invention: selfing,backcrosses, hybrid production, crosses to populations, and the like.All plants produced using inbred maize line PH0AA as a parent are withinthe scope of this invention. Advantageously, the inbred maize line isused in crosses with other, different, maize inbreds to produce firstgeneration (F₁) maize hybrid seeds and plants with superiorcharacteristics.

As used herein, the term plant includes plant cells, plant protoplasts,plant cell tissue cultures from which maize plants can be regenerated,plant calli, plant clumps, and plant cells that are intact in plants orparts of plants, such as embryos, pollen, ovules, flowers, kernels,ears, cobs, leaves, husks, stalks, roots, root tips, anthers, silk andthe like.

Duncan, Williams, Zehr, and Widholm, Planta (1985) 165:322-332 reflectsthat 97% of the plants cultured that produced callus were capable ofplant regeneration. Subsequent experiments with both inbreds and hybridsproduced 91% regenerable callus that produced plants. In a further studyin 1988, Songstad, Duncan & Widholm in Plant Cell Reports (1988),7:262-265 reports several media additions that enhance regenerability ofcallus of two inbred lines. Other published reports also indicated that"nontraditional" tissues are capable of producing somatic embryogenesisand plant regeneration. K. P. Rao, et al., Maize Genetics CooperationNewsletter, 60:64-65 (1986), refers to somatic embryogenesis from glumecallus cultures and B. V. Conger, et al., Plant Cell Reports, 6:345-347(1987) indicates somatic embryogenesis from the tissue cultures of maizeleaf segments. Thus, it is clear from the literature that the state ofthe art is such that these methods of obtaining plants are, and were,"conventional" in the sense that they are routinely used and have a veryhigh rate of success.

Tissue culture of maize is described in European Patent Application,publication 160,390, incorporated herein by reference. Maize tissueculture procedures are also described in Green and Rhodes, "PlantRegeneration in Tissue Culture of Maize," Maize for Biological Research(Plant Molecular Biology Association, Charlottesville, Va. 1982, at367-372) and in Duncan, et al., "The Production of Callus Capable ofPlant Regeneration from Immature Embryos of Numerous Zea MaysGenotypes," 165 Planta 322-332 (1985). Thus, another aspect of thisinvention is to provide cells which upon growth and differentiationproduce maize plants having the physiological and morphologicalcharacteristics of inbred line PH0AA.

Maize is used as human food, livestock feed, and as raw material inindustry. The food uses of maize, in addition to human consumption ofmaize kernels, include both products of dry- and wet-milling industries.The principal products of maize dry milling are grits, meal and flour.The maize wet-milling industry can provide maize starch, maize syrups,and dextrose for food use. Maize oil is recovered from maize germ, whichis a by-product of both dry- and wet-milling industries.

Maize, including both grain and non-grain portions of the plant, is alsoused extensively as livestock feed, primarily for beef cattle, dairycattle, hogs, and poultry.

Industrial uses of maize include production of ethanol, maize starch inthe wet-milling industry and maize flour in the dry-milling industry.The industrial applications of maize starch and flour are based onfunctional properties, such as viscosity, film formation, adhesiveproperties, and ability to suspend particles. The maize starch and flourhave application in the paper and textile industries. Other industrialuses include applications in adhesives, building materials, foundrybinders, laundry starches, explosives, oil-well muds, and other miningapplications.

Plant parts other than the grain of maize are also used in industry: forexample, stalks and husks are made into paper and wallboard and cobs areused for fuel and to make charcoal.

The seed of inbred maize line PH0AA, the plant produced from the inbredseed, the hybrid maize plant produced from the crossing of the inbred,hybrid seed, and various parts of the hybrid maize plant can be utilizedfor human food, livestock feed, and as a raw material in industry.

Performance Examples of PH0AA

In the examples that follow, the traits and characteristics of inbredmaize line PH0AA are presented as an inbred per se and in hybridcombination. The data collected on inbred maize line PH0AA is presentedfor key characteristics and traits.

The results in Table 2A compare PH0AA to one of its parents, PHJ89. Bothinbreds demonstrate good seedling vigor and early stand count. Theresults show inbred PH0AA has greater resistance to root lodging andbrittle stalk, which are very important traits in it's area ofadaptation, than Inbred PHJ89. Additionally, Inbred PH0AA demonstratesslightly shorter plant height when compared to inbred PHJ89.

The results in Table 2B compare PH0AA to PHTM9, a similarly adaptedinbred line. The results show inbred PH0AA has a higher yield and betterseedling vigor than inbred PHTM9. Inbred PH0AA demonstrates a betterearly stand count and better stay green than inbred PHTM9. Inbred PH0AAalso exhibits a larger ear size and better resistance to Northern LeafBlight than inbred PHTM9.

The results in Table 2C compare PH0AA to PHK56, a similarly adaptedinbred line. The results show inbred PH0AA has a higher yield, lowermoisture and significantly better seedling vigor than inbred PHK56.Inbred PH0AA demonstrates a significantly better early stand count andbetter ear texture than inbred PHK56.

The results in Table 3 compare the inbred by tester performance of PH0AAto PHJ89. The results show that hybrids developed from PH0AA have lowerharvest moisture and better resistance to root lodging than the hybridsdeveloped from PHJ89. The hybrids developed from PH0AA also demonstratesbetter resistance to brittle stalk than the hybrids developed fromPHJ89.

The results in Table 4 compare a hybrid developed from PH0AA,PH0AA/PHAP8, and a similarly adapted hybrid with an identical parent,PHRE1/PHAP8. The results show that while both hybrids demonstrate goodseedling vigor, the hybrid PH0AA/PHAP8 demonstrates better staygreen andbetter resistance to brittle stalk than the hybrid PHRE1/PHAP8. Thehybrid PH0AA/PHAP8 is higher yielding more and has better resistance toroot lodging than the hybrid PHRE1/PHAP8.

                                      TABLE 2A                                    __________________________________________________________________________    PAIRED INBRED COMPARISON REPORT                                               VARIETY #1 = PH00A                                                            VARIETY #2 = PHJ89                                                            __________________________________________________________________________               BU BU     TST                                                                              SDG                                                                              EST                                                                              TIL                                                                              GDU                                                                              GDU                                                  ACR                                                                              ACR MST                                                                              WT VGR                                                                              CNT                                                                              LER                                                                              SHD                                                                              SLK                                                  ABS                                                                              % MN                                                                              ABS                                                                              ABS                                                                              ABS                                                                              ABS                                                                              ABS                                                                              ABS                                                                              ABS                                       __________________________________________________________________________    TOTAL SUM                                                                            1   43.5                                                                             91  15.2                                                                             58.8                                                                             5.4                                                                              35.6                                                                             0.7                                                                              135.4                                                                            136.2                                            2   41.4                                                                             88  15.9                                                                             59.8                                                                             5.4                                                                              35.6                                                                             0.4                                                                              131.8                                                                            132.4                                            LOCS                                                                              3  3   3  3  25 32 28 39 39                                               REPS                                                                              5  5   5  5  27 36 32 42 42                                               DIFF                                                                              2.1                                                                              3   0.7                                                                              1.0                                                                              0.1                                                                              0.0                                                                              0.3                                                                              3.6                                                                              3.8                                              PR > T                                                                            .710                                                                             .776                                                                              .241                                                                             .434                                                                             .791                                                                             .999                                                                             .345                                                                             .000#                                                                            .000#                                     __________________________________________________________________________               POL                                                                              POL POL                                                                              TAS                                                                              TAS                                                                              PLT                                                                              EAR                                                                              RT STA                                                  WT WT  SC BLS                                                                              SZ HT HT LDG                                                                              GRN                                                  ABS                                                                              % MN                                                                              ABS                                                                              ABS                                                                              ABS                                                                              ABS                                                                              ABS                                                                              ABS                                                                              ABS                                       __________________________________________________________________________    TOTAL SUM                                                                            1   100.0                                                                            99  5.6                                                                              9.0                                                                              5.2                                                                              69.1                                                                             23.5                                                                             97.0                                                                             3.6                                              2   142.3                                                                            142 6.3                                                                              8.0                                                                              5.8                                                                              74.8                                                                             25.1                                                                             89.8                                                                             4.9                                              LOCS                                                                              5  5   8  1  12 18 16 4  6                                                REPS                                                                              5  5   8  1  13 21 19 4  8                                                DIFF                                                                              42.3                                                                             43  0.7                                                                              1.0                                                                              0.7                                                                              5.7                                                                              1.6                                                                              7.2                                                                              1.3                                              PR > T                                                                            .019+                                                                            .022+                                                                             .204  .054*                                                                            .000#                                                                            .124                                                                             .391                                                                             .262                                      __________________________________________________________________________               STK                                                                              BRT GRN                                                                              SCT                                                                              EAR                                                                              TEX                                                                              EAR                                                                              BAR                                                                              DRP                                                  LDG                                                                              STK APP                                                                              GRN                                                                              SZ EAR                                                                              MLD                                                                              PLT                                                                              EAR                                                  ABS                                                                              ABS ABS                                                                              ABS                                                                              ABS                                                                              ABS                                                                              ABS                                                                              ABS                                                                              ABS                                       __________________________________________________________________________    TOTAL SUM                                                                            1   95.8                                                                             94.8                                                                              7.0                                                                              7.1                                                                              3.7                                                                              6.7                                                                              7.0                                                                              93.0                                                                             99.2                                             2   97.5                                                                             91.7                                                                              8.2                                                                              7.3                                                                              5.3                                                                              6.0                                                                              7.7                                                                              92.6                                                                             98.2                                             LOCS                                                                              4  4   3  7  3  3  7  11 3                                                REPS                                                                              7  4   5  8  3  3  8  11 6                                                DIFF                                                                              1.7                                                                              3.2 1.2                                                                              0.1                                                                              1.7                                                                              0.7                                                                              0.7                                                                              0.3                                                                              1.0                                              PR > T                                                                            .445                                                                             .540                                                                              .336                                                                             .859                                                                             .038+                                                                            .184                                                                             .394                                                                             .905                                                                             .664                                      __________________________________________________________________________               GLF                                                                              NLF STW                                                                              HD EYE                                                                              ECB                                                                              ECB                                                        SPT                                                                              BLT WLT                                                                              SMT                                                                              SPT                                                                              1LF                                                                              2SC                                                        ABS                                                                              ABS ABS                                                                              ABS                                                                              ABS                                                                              ABS                                                                              ABS                                             __________________________________________________________________________    TOTAL SUM                                                                            1   3.0                                                                              7.5 2.0                                                                              100.0                                                                            7.0                                                                              4.3                                                                              3.0                                                    2   3.0                                                                              8.0 2.0                                                                              100.0                                                                            8.0                                                                              4.6                                                                              5.0                                                    LOCS                                                                              1  2   1  1  1  7  2                                                      REPS                                                                              1  2   1  2  1  7  2                                                      DIFF                                                                              0.0                                                                              0.5 0.0                                                                              0.0                                                                              1.0                                                                              0.3                                                                              2.0                                                    PR > T .m500        .522                                                                             .500                                            __________________________________________________________________________     * = 10% SIG                                                                   + = 5% SIG                                                                    # = 1% SIG                                                               

                                      TABLE 2B                                    __________________________________________________________________________    PAIRED INBRED COMPARISON REPORT                                               VARIETY #1 = PH0AA                                                            VARIETY #2 = PHTM9                                                            __________________________________________________________________________               BU BU     TST                                                                              SDG                                                                              EST                                                                              TIL                                                                              GDU                                                                              GDU                                                  ACR                                                                              ACR MST                                                                              WT VGR                                                                              CNT                                                                              LER                                                                              SHD                                                                              SLK                                                  ABS                                                                              % MN                                                                              ABS                                                                              ABS                                                                              ABS                                                                              ABS                                                                              ABS                                                                              ABS                                                                              ABS                                       __________________________________________________________________________    TOTAL SUM                                                                            1   43.5                                                                             91  15.2                                                                             58.8                                                                             5.6                                                                              38.0                                                                             0.6                                                                              133.9                                                                            134.9                                            2   29.7                                                                             61  15.8                                                                             59.2                                                                             5.1                                                                              35.4                                                                             0.6                                                                              126.0                                                                            128.8                                            LOCS                                                                              3  3   3  3  20 27 26 37 37                                               REPS                                                                              5  5   5  5  22 31 30 40 40                                               DIFF                                                                              13.8                                                                             30  0.6                                                                              0.4                                                                              0.5                                                                              2.6                                                                              0.0                                                                              8.0                                                                              6.1                                              PR > T                                                                            .027+                                                                            .045+                                                                             .159                                                                             .729                                                                             .271                                                                             .213                                                                             .999                                                                             .000#                                                                            .000#                                     __________________________________________________________________________               POL                                                                              POL POL                                                                              TAS                                                                              TAS                                                                              PLT                                                                              EAR                                                                              RT STA                                                  WT WT  SC BLS                                                                              SZ HT HT LDG                                                                              GRN                                                  ABS                                                                              %MN.                                                                              ABS                                                                              ABS                                                                              ABS                                                                              ABS                                                                              ABS                                                                              ABS                                                                              ABS                                       __________________________________________________________________________    TOTAL SUM                                                                            1   104.3                                                                            94  6.0                                                                              9.0                                                                              5.1                                                                              69.2                                                                             23.6                                                                             96.0                                                                             4.1                                              2   93.6                                                                             86  4.8                                                                              8.5                                                                              4.8                                                                              76.1                                                                             25.6                                                                             93.9                                                                             1.8                                              LOCS                                                                              9  9   9  1  12 20 19 3  4                                                REPS                                                                              9  9   9  1  13 23 22 3  6                                                DIFF                                                                              10.7                                                                             8   1.2                                                                              0.5                                                                              0.3                                                                              6.9                                                                              2.0                                                                              2.1                                                                              2.4                                              PR > T                                                                            .578                                                                             .654                                                                              .058* .339                                                                             .000#                                                                            .029+                                                                            .324                                                                             .077*                                     __________________________________________________________________________               STK                                                                              BRT GRN                                                                              SCT                                                                              EAR                                                                              TEX                                                                              EAR                                                                              BAR                                                                              DRP                                                  LDG                                                                              STK APP                                                                              GRN                                                                              SZ EAR                                                                              MLD                                                                              PLT                                                                              EAR                                                  ABS                                                                              ABS ABS                                                                              ABS                                                                              ABS                                                                              ABS                                                                              ABS                                                                              ABS                                                                              ABS                                       __________________________________________________________________________    TOTAL SUM                                                                            1   95.8                                                                             94.8                                                                              7.0                                                                              7.0                                                                              4.0                                                                              7.7                                                                              6.6                                                                              93.0                                                                             99.2                                             2   94.3                                                                             96.9                                                                              6.7                                                                              8.0                                                                              2.0                                                                              6.3                                                                              8.2                                                                              92.0                                                                             99.3                                             LOCS                                                                              4  4   3  5  2  3  5  11 3                                                REPS                                                                              7  4   5  6  2  3  6  11 6                                                DIFF                                                                              1.5                                                                              2.0 0.3                                                                              1.0                                                                              2.0                                                                              1.3                                                                              1.6                                                                              1.1                                                                              0.1                                              PR > T                                                                            .240                                                                             .182                                                                              .423                                                                             .266                                                                             .000#                                                                            .270                                                                             .099*                                                                            .718                                                                             .903                                      __________________________________________________________________________               NLF                                                                              HD  ECB                                                                              ECB                                                                 BLT                                                                              SMT 1LF                                                                              2SC                                                                 ABS                                                                              ABS ABS                                                                              ABS                                                      __________________________________________________________________________    TOTAL SUM                                                                            1   8.0                                                                              100.0                                                                             4.3                                                                              3.0                                                             2   1.0                                                                              100.0                                                                             4.5                                                                              4.0                                                             LOCS                                                                              1  1   4  2                                                               REPS                                                                              1  2   4  2                                                               DIFF                                                                              7.0                                                                              0.0 0.3                                                                              1.0                                                             PR > T     .391                                                                             .500                                                     __________________________________________________________________________     * = 10% SIG                                                                   + = 5% SIG                                                                    # = 1% SIG                                                               

                                      TABLE 2C                                    __________________________________________________________________________    PAIRED INBRED COMPARISON REPORT                                               VARIETY #1 = PH0AA                                                            VARIETY #2 = PHK56                                                            __________________________________________________________________________               BU BU     TST                                                                              SDG                                                                              EST                                                                              TIL                                                                              GDU                                                                              GDU                                                  ACR                                                                              ACR MST                                                                              WT VGR                                                                              CNT                                                                              LER                                                                              SHD                                                                              SLK                                                  ABS                                                                              % MN                                                                              ABS                                                                              ABS                                                                              ABS                                                                              ABS                                                                              ABS                                                                              ABS                                                                              ABS                                       __________________________________________________________________________    TOTAL SUM                                                                            1   43.5                                                                             91  15.2                                                                             58.8                                                                             5.3                                                                              32.8                                                                             1.3                                                                              137.0                                                                            138.3                                            2   42.9                                                                             83  18.8                                                                             56.3                                                                             3.3                                                                              24.2                                                                             1.3                                                                              143.8                                                                            147.2                                            LOCS                                                                              3  3   3  3  20 31 26 34 34                                               REPS                                                                              5  5   5  5  22 34 29 37 37                                               DIFF                                                                              0.6                                                                              8   3.6                                                                              2.5                                                                              2.0                                                                              8.7                                                                              0.0                                                                              6.8                                                                              9.0                                              PR > T                                                                            .968                                                                             .779                                                                              .091*                                                                            .274                                                                             .000#                                                                            .000#                                                                            .999                                                                             .000#                                                                            .000#                                     __________________________________________________________________________               POL                                                                              POL POL                                                                              TAS                                                                              TAS                                                                              PLT                                                                              EAR                                                                              RT STA                                                  WT WT  SC BLS                                                                              SZ HT HT LDG                                                                              GRN                                                  ABS                                                                              % MN                                                                              ABS                                                                              ABS                                                                              ABS                                                                              ABS                                                                              ABS                                                                              ABS                                                                              ABS                                       __________________________________________________________________________    TOTAL SUM                                                                            1   99.4                                                                             99  5.7                                                                              9.0                                                                              5.0                                                                              70.1                                                                             23.3                                                                             97.0                                                                             3.1                                              2   129.8                                                                            128 5.9                                                                              9.0                                                                              5.9                                                                              85.9                                                                             32.5                                                                             100.0                                                                            6.6                                              LOCS                                                                              6  6   9  1  12 15 13 4  8                                                REPS                                                                              6  6   9  1  13 18 16 4  10                                               DIFF                                                                              30.3                                                                             29  0.3                                                                              0.0                                                                              0.9                                                                              15.7                                                                             9.2                                                                              3.0                                                                              3.5                                              PR > T                                                                            .221                                                                             .238                                                                              .578  .009#                                                                            .000#                                                                            .000#                                                                            .391                                                                             .005#                                     __________________________________________________________________________               STK                                                                              BRT GRN                                                                              SCT                                                                              EAR                                                                              TEX                                                                              EAR                                                                              RAR                                                                              DRP                                                  LDG                                                                              STK APP                                                                              GRN                                                                              SZ EAR                                                                              MLD                                                                              PLT                                                                              EAR                                                  ABS                                                                              ABS ABS                                                                              ABS                                                                              ABS                                                                              ABS                                                                              ABS                                                                              ABS                                                                              ABS                                       __________________________________________________________________________    TOTAL SUM                                                                            1   94.9                                                                             93.1                                                                              7.0                                                                              6.8                                                                              3.6                                                                              7.0                                                                              7.0                                                                              92.9                                                                             99.2                                             2   88.1                                                                             100.0                                                                             6.3                                                                              7.5                                                                              5.8                                                                              4.3                                                                              7.8                                                                              94.4                                                                             100.0                                            LOCS                                                                              4  3   3  6  5  3  6  12 3                                                REPS                                                                              6  3   5  7  5  3  7  12 5                                                DIFF                                                                              6.8                                                                              6.9 0.7                                                                              0.7                                                                              2.2                                                                              2.7                                                                              0.8                                                                              1.5                                                                              0.8                                              PR > T                                                                            .151                                                                             .304                                                                              .184                                                                             .444                                                                             .040+                                                                            .094*                                                                            .383                                                                             .696                                                                             .423                                      __________________________________________________________________________               GLF                                                                              NLF STW                                                                              ECB                                                                              ECB                                                              SPT                                                                              BLT WLT                                                                              1LF                                                                              2SC                                                              ABS                                                                              ABS ABS                                                                              ABS                                                                              ABS                                                   __________________________________________________________________________    TOTAL SUM                                                                            1   3.0                                                                              8.0 2.0                                                                              4.3                                                                              3.0                                                          2   5.0                                                                              7.0 5.0                                                                              4.4                                                                              5.0                                                          LOCS                                                                              1  1   1  7  2                                                            REPS                                                                              1  1   1  7  2                                                            DIFF                                                                              2.0                                                                              1.0 3.0                                                                              0.1                                                                              2.0                                                          PR > T        .736                                                                             .295                                                  __________________________________________________________________________     * = 10% SIG                                                                   + = 5% SIG                                                                    # = 1% SIG                                                               

                                      TABLE 3                                     __________________________________________________________________________    Average Inbred By Tester Performance Comparing PH0AA To PHJ89 Crossed         To The Same Inbred Testers And Grown In The Same Experiments.                 __________________________________________________________________________                SEL     BU  BU  PRM     TST SDG EST GDU                                       IND PRM ACR ACR SHD MST WT  VGR CNT SHD                                       % MN                                                                              ABS ABS % MN                                                                              ABS % MN                                                                              ABS % MN                                                                              % MN                                                                              % MN                          __________________________________________________________________________    TOTAL SUM                                                                            REPS 5   4   37  37  7   39  21  11  27  12                                   LOCS 5   4   37  37  7   39  21  11  27  12                                   PH0AA                                                                              96  99  149 95  98  95  55  97  94  99                                   PHJ89                                                                              103 101 149 96  100 100 55  105 102 100                                  DIFF 7   2   0   0   2   5   0   8   8   2                                    PR > T                                                                             0.24                                                                              0.08                                                                              0.97                                                                              0.92                                                                              0.22                                                                              0.00                                                                              0.65                                                                              0.47                                                                              0.00                                                                              0.07                          __________________________________________________________________________                GDU STK PLT EAR RT  STA STK BRT ECB ECB                                       SLK CNT HT  HT  .LDG                                                                              GRN LDG STK DPE 1LF                                       % MN                                                                              % MN                                                                              % MN                                                                              % MN                                                                              % MN                                                                              *% MN                                                                             % MN                                                                              % MN                                                                              ABS ABS                           __________________________________________________________________________    TOTAL SUM                                                                            REPS 8   40  17  17  15  15  34  5   7   2                                    LOCS 8   40  17  17  15  15  34  5   7   2                                    PH0AA                                                                              99  97  100 98  106 78  98  107 100 4                                    PHJ89                                                                              101 103 103 98  101 95  99  102 99  4                                    DIFF 2   6   3   0   5   17  1   4   1   1                                    PR > T                                                                             0.00                                                                              0.00                                                                              0.04                                                                              0.98                                                                              0.08                                                                              0.05                                                                              0.48                                                                              0.23                                                                              0.17                                                                              0.87                          __________________________________________________________________________                ECB DRP                                                                       2SC EAR                                                                       ABS % MN                                                          __________________________________________________________________________    TOTAL SUM                                                                            REPS 1   33                                                                   LOCS 1   33                                                                   PH0AA                                                                              6   100                                                                  PHJ89                                                                              7   100                                                                  DIFF 1   0                                                                    PR > T   0.60                                                          __________________________________________________________________________     *PR > T values are valid only for comparisons with Locs >= 10.           

                                      TABLE 4                                     __________________________________________________________________________    VARIETY #1 = PH0AA/PHAP8                                                      VARIETY #2 = PHRE1/PHAP8                                                      __________________________________________________________________________                   PRM BU  BU      TST SDG EST GDU                                           PRM SHD ACR ACR MST WT  VGR CNT SHD                                           ABS ABS ABS % MN                                                                              % MN                                                                              ABS % MN                                                                              % MN                                                                              % MN                               __________________________________________________________________________    TOTAL SUM                                                                            1   97  99  135.4                                                                             99  99  56.2                                                                              104 101 100                                       2   93  95  128.4                                                                             95  91  57.1                                                                              102 102 95                                        LOCS                                                                              9   9   37  37  38  21  23  28  10                                        REPS                                                                              9   9   85  85  86  49  32  60  15                                        DIFF                                                                              3   4   7.0 5   8   0.9 1   1   4                                         PR > T                                                                            .000#                                                                             .000#                                                                             .023+                                                                             .031+                                                                             .000#                                                                             .005#                                                                             .849                                                                              .145                                                                              .000#                              __________________________________________________________________________               GDU STK PLT EAR RT  STA STK BRT GRN                                           SLK CNT HT  HT  LDG GRN LDG STK APP                                           % MN                                                                              % MN                                                                              % MN                                                                              % MN                                                                              % MN                                                                              % MN                                                                              % MN                                                                              % MN                                                                              % MN                               __________________________________________________________________________    TOTAL SUM                                                                            1   99  101 99  90  103 112 103 106 115                                       2   94  100 95  95  93  80  101 96  108                                       LOCS                                                                              7   49  13  13  14  13  30  10  5                                         REPS                                                                              11  97  18  18  23  17  63  16  19                                        DIFF                                                                              4   1   4   5   10  32  2   10  7                                         PR > T                                                                            .001#                                                                             .242                                                                              .036+                                                                             .099*                                                                             .219                                                                              .001#                                                                             .226                                                                              .032+                                                                             .316                               __________________________________________________________________________               DRP HD  ECB ECB ECB                                                           EAR SMT DPE 1LF 2SC                                                           % MN                                                                              ABS ABS ABS ABS                                                __________________________________________________________________________    TOTAL SUM                                                                            1   100 91.9                                                                              98.6                                                                              3.0 6.0                                                       2   100 97.2                                                                              94.2                                                                              6.0 6.0                                                       LOCS                                                                              19  1   7   1   1                                                         REPS                                                                              46  2   11  1   1                                                         DIFF                                                                              0   5.3 4.4 3.0 0.0                                                       PR > T                                                                            .999    .239                                                       __________________________________________________________________________     * = 10% SIG                                                                   + = 5% SIG                                                                    # = 1% SIG                                                               

Deposits

Applicant has made a deposit of at least 2500 seeds of Inbred Corn LinePH0AA with the American Type Culture Collection (ATCC), Rockville, Md.20852 USA, ATCC Deposit No. 209266. The seeds deposited with the ATCC onSep. 15, 1997 were taken from the deposit maintained by Pioneer Hi-BredInternational, Inc., 700 Capital Square, 400 Locust Street, Des Moines,Iowa 50309-2340 since prior to the filing date of this application. Thisdeposit of the Inbred Corn Line PH0AA will be maintained in the ATCCdepository, which is a public depository, for a period of 30 years, or 5years after the most recent request, or for the effective life of thepatent, whichever is longer, and will be replaced if it becomesnonviable during that period. Additionally, Applicant has satisfied allthe requirements of 37 C.F.R. §§1.801-1.809, including providing anindication of the viability of the sample. Applicant imposes norestrictions on the availability of the deposited material from theATCC; however, Applicant has no authority to waive any restrictionsimposed by law on the transfer of biological material or itstransportation in commerce. Applicant does not waive any infringement ofits rights granted under this patent or under the Plant VarietyProtection Act (7 USC 2321 et seq.). Applicant has applied for U.S.Plant Variety Protection of PH0AA under Application No. 9600199.

The foregoing invention has been described in detail by way ofillustration and example for purposes of clarity and understanding.However, it will be obvious that certain changes and modifications suchas single gene modifications and mutations, somoclonal variants, variantindividuals selected from large populations of the plants of the instantinbred and the like may be practiced within the scope of the invention,as limited only by the scope of the appended claims.

what is claimed is:
 1. Seed of maize inbred line designated PH0AA havingbeen deposited under ATCC Accession No.
 209266. 2. A maize plant, orparts thereof, of inbred line PH44A, seed of said line having beendeposited under ATCC accession No.
 209266. 3. Pollen of the plant ofclaim
 2. 4. An ovule of the plant of claim
 2. 5. A maize plant, or partsthereof, having all the physiological and morphological characteristicsof the plant of claim
 2. 6. A male sterile maize plant, or partsthereof, otherwise having all the physiological and morphologicalcharacteristics of the plant of claim
 2. 7. A tissue culture ofregenerable cells of a maize plant of inbred line PH0AA, seed of saidinbred line having been deposited under ATCC Accession No. 209266,wherein the tissue regenerates plants capable of expressing all themorphological and physiological characteristics of plants of said inbredline PH0AA.
 8. A tissue culture according to claim 7, the cells orprotoplasts being of a tissue selected from the group consisting ofleaves, pollen, embryos, roots, root tips, anthers, silks, flowers,kernels, ears, cobs, husks, and stalks.
 9. A maize plant regeneratedfrom the tissue culture of claim 7, capable of expressing all themorphological and physiological characteristics of inbred line PH0AA,seed of said inbred line having been deposited under ATCC Accession No.209266.
 10. A method for producing a first generation (F₁) hybrid maizeseed comprising crossing the plant of claim 2 with a different inbredparent maize plant and harvesting the resultant first generation (F₁)hybrid maize seed.
 11. The method of claim 10 wherein inbred maize plantof claim 2 is the female parent.
 12. The method of claim 10 whereininbred maize plant of claim 2 is the male parent.
 13. A method forproducing a first generation (F₁) hybrid maize seed comprising crossingthe plant of claim 5 with a different inbred parent maize plant andharvesting the resultant first generation (F₁) hybrid maize seed. 14.The method of claim 13 wherein inbred maize plant of claim 5 is thefemale parent.
 15. The method of claim 13 wherein inbred maize plant ofclaim 5 is the male parent.
 16. An F₁ hybrid seed produced by crossingthe inbred maize plant according to claim 2 with another, differentmaize plant.
 17. An F₁ hybrid plant, or parts thereof, grown from theseed of claim
 16. 18. An F₁ hybrid seed produced by crossing the inbredmaize plant according to claim 5 with another, different maize plant.19. An F₁ hybrid plant, or parts thereof, grown from the seed of claim18.